To the Editor: The article by Roxanas and colleagues1 is a welcome addition to the body of literature that clearly demonstrates a causal relationship between lithium use and chronic renal failure. The recommendation to monitor renal function 6-monthly and be hypervigilant to deteriorating renal function is sound clinical advice.
However, I question the recommendation that clinicians should consider stopping lithium and using other suitable mood stabilisers (eg, sodium valproate) if two consecutive readings suggest decrease in renal function, or if the estimated glomerular filtration rate is < 45 mL/min/1.73 m2.
I believe it is more clinically prudent to refer patients who have deteriorating renal function to a nephrologist, who can determine the cause.
I do this routinely and two trends have emerged. The first is that most but not all individuals who are taking lithium and who have deteriorating renal function have interstitial fibrosis, the putative renal abnormality caused by lithium.
When individuals with interstitial fibrosis are switched from lithium to other mood stabilisers, many have a stormy clinical course and never achieve the mood stability they had previously experienced with lithium.